KR20190048833A - Organic light emitting diodes display - Google Patents

Abstract

The present invention relates to an organic light emitting display device, which has improved light extraction efficiency. According to the present invention, a reflection barrier having a reflection side surface of a reverse taper is positioned to correspond to a non-light emitting area defined by an edge of a light emitting area of each sub-pixel. Accordingly, light travelling the non-light emitting area among lights emitted from each sub-pixel is reflected to be extracted to the outside of a substrate, thereby improving the light extraction efficiency of an OLED. Also, the leakage of light reflected and generated from adjacent sub-pixels can be minimized, and the light reflected and generated from the adjacent sub-pixels is reflected again to be extracted to the outside, thereby further improving the light extraction efficiency of the OLED.

Description

[0001] The present invention relates to organic light emitting diodes

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an organic light emitting display, and more particularly, to an organic light emitting display having improved light extraction efficiency.

Recently, as the society has become a full-fledged information age, interest in information display processing and displaying a large amount of information has increased, and a demand for using portable information media has increased, and the display field has rapidly developed And various lightweight and thin flat panel display devices have been developed in response to this.

Specific examples of such flat panel display devices include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display (FED) (ELD), organic light emitting diodes (OLED), and the like. These flat panel display devices are excellent in performance of thinning, light weight, and low power consumption. Thus, the conventional cathode ray tube CRT).

Of the above flat panel display devices, an organic light emitting display (hereinafter referred to as OLED) is a self-luminous device and can be lightweight and thin because it does not require a backlight used in a liquid crystal display device which is a non-light emitting device.

In addition, it has a better viewing angle and contrast ratio than liquid crystal display devices, is advantageous in terms of power consumption, can be driven by DC low voltage, has a fast response speed, is resistant to external impacts due to its solid internal components, It has advantages.

Particularly, since the manufacturing process is simple, it is advantageous in that the production cost can be saved more than the conventional liquid crystal display device.

Such an OLED is a self-luminous element that emits light through a light emitting diode, and the light emitting diode emits light through organic electroluminescence.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a band diagram of a light emitting diode having a light emitting principle by a general organic electroluminescence phenomenon.

As shown in the figure, the light emitting diode 10 includes anode and cathode electrodes 21 and 25 and an organic light emitting layer disposed therebetween. The organic light emitting layer includes a hole transport layer (HTL) An electron transport layer (ETL) 35, and an emission material layer (EML) 40 interposed between the hole transporting film 33 and the electron transporting film 35.

A hole injecting layer (HIL) 37 is interposed between the anode electrode 21 and the hole transporting layer 33 to improve the luminous efficiency. The cathode electrode 25 and the electron transporting layer 35 are interposed between the anode electrode 21 and the hole transporting layer 33, An electron injection layer (EIL) 39 is interposed therebetween.

In this light emitting diode 10, when positive and negative voltages are applied to the anode electrode 21 and the cathode electrode 25, the holes of the anode electrode 21 and the electrons of the cathode electrode 25 The excitons are transported to the luminescent film 40 to form excitons. When the excitons are transited from the excited state to the ground state, light is generated and emitted by the luminescent film 40 in the form of visible light.

However, the OLED including the light emitting diode 10 is largely lost in the process of emitting light emitted from the organic light emitting layer through various components of the OLED to the outside, and light emitted to the outside of the OLED is emitted from the organic light emitting layer Only about 20% of the emitted light is emitted.

Here, since the amount of light emitted from the organic light emitting layer increases along with the amount of current applied to the OLED, it is possible to increase the brightness of the OLED by applying more current to the organic light emitting layer. However, It also reduces the lifetime of the OLED.

Therefore, various studies are needed to improve the light extraction efficiency of OLED.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an OLED having improved light extraction efficiency.

The second object is to prevent light leakage.

In order to achieve the above object, according to the present invention, there is provided a liquid crystal display device comprising a substrate including a light emitting region and a plurality of sub-pixels each of which defines a non-light emitting region along an edge of the light emitting region, An overcoat layer disposed over the reflective barrier, a first electrode sequentially disposed on the overcoat layer, an organic light emitting layer, and a second electrode, The reflective barrier includes an inverse tapered reflective side so that a width of the reflective barrier is narrow toward the direction of light emitted from the organic light emitting layer.

At this time, the reflective barrier ribs are formed in a rectangular shape along the edges of the respective light emitting regions, and include a reflective layer on each of the both side surfaces and the upper surface, and both side surfaces constituting the reflective side surface and an upper surface connecting the both side surfaces. , And the reflective barrier is at least one of an inverted trapezoidal shape or an inverted triangular shape in which the width increases as the distance from the substrate increases.

A reverse taper angle between the substrate and the reflective side is in a range of 45 to 90 degrees. The first electrode is located in each sub-pixel, and the bank is positioned in the non-emission region along the edge of the first electrode. And the width of the reflective barrier rib is narrower than the width of the bank.

The plurality of sub-pixels include a red sub-pixel having a red color filter, a green sub-pixel having a green color filter, and a blue sub-pixel having a blue color filter on the light emitting region, The driving thin film transistor includes a semiconductor layer, a gate insulating film located above the semiconductor layer, a gate electrode located above the gate insulating film, a first interlayer insulating film located above the gate electrode, And a source electrode and a drain electrode located above the first interlayer insulating film. The red, green, and blue color filters are located above the second interlayer insulating film located above the source and drain electrodes.

As described above, according to the present invention, by positioning the reflective barrier having the reflective side of the inverse taper corresponding to the non-emission region defined along the edge of the emission region of each sub-pixel, The light traveling to the non-light emitting region can be reflected and extracted to the outside of the substrate, thereby improving the light extraction efficiency of the OLED.

In addition, the light leakage generated by reflection from adjacent sub-pixels can be minimized. Further, the light reflected from adjacent sub-pixels is reflected back to be extracted to the outside, thereby further improving the light extraction efficiency of the OLED .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a band diagram of a light emitting diode having an emission principle by a general organic electroluminescent phenomenon. FIG.
2 is a plan view showing the structure of a unit pixel including three sub-pixels in an OLED according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating a structure of a unit pixel including three sub-pixels of an OLED according to an embodiment of the present invention, cut along a cutting line II-II line in FIG.
4 is a view schematically showing a light guide of an OLED according to an embodiment of the present invention.
5A is a simulation result of measuring a light guide of an OLED not including a reflective barrier.
5B to 5E are simulation results of measuring the light guided state of the OLED in which the reflective barrier is located according to the embodiment of the present invention.
6 is a cross-sectional view schematically showing a reflective barrier according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

2 is a plan view showing the structure of one unit pixel including three sub-pixels in an OLED according to an embodiment of the present invention.

3 is a cross-sectional view of one unit pixel (R-SP, G-SP, B-SP) including three sub-pixels R-SP, G-SP, and B-SP of the OLED according to the embodiment of the present invention cut along the cutting line II- P shown in Fig.

The OLED 100 according to an embodiment of the present invention is divided into a top emission type and a bottom emission type according to the transmission direction of emitted light. I will explain the method as an example.

2, an OLED 100 according to an exemplary embodiment of the present invention includes red, green, and blue sub-pixels R-SP, G-SP, and B- Each of the sub-pixels R-SP, G-SP, and B-SP includes a light emitting region EA. A bank 119 is disposed along the edge of the light emitting region EA, (NEA).

Although the sub-pixels R-SP, G-SP, and B-SP are arranged at the same width for convenience of description, SP) can have various structures with different widths.

At this time, the switching and driving thin film transistors STr and DTr are provided on the non-emission region NEA of each of the sub-pixels R-SP, G-SP, and B- Emitting diodes E including a first electrode 111, an organic light-emitting layer 113 and a second electrode 115 are arranged on a light-emitting region EA in the pixel electrodes SP and B-SP.

Here, the switching thin film transistor STr and the driving thin film transistor DTr are connected to each other, and the driving thin film transistor DTr is connected to the light emitting diode E.

The gate line SL, the data line DL and the power supply line VDD are arranged on the substrate 101 to define the respective sub-pixels R-SP, G-SP, and B-SP. do.

The switching thin film transistor STr is formed at a portion where the gate line SL and the data line DL intersect each other. The switching thin film transistor STr is connected to the sub-pixels R-SP, G-SP, and B- As shown in FIG.

The switching thin film transistor STr includes a gate electrode SG branched from the gate wiring GL, a semiconductor layer 103, a source electrode SS and a drain electrode SD.

The driving thin film transistor DTr drives the light emitting diodes E of the sub-pixels R-SP, G-SP, and B-SP selected by the switching thin film transistor STr. The driving thin film transistor DTr includes a gate electrode DG connected to the drain electrode SD of the switching thin film transistor STr, a source electrode DS connected to the semiconductor layer 103, the power supply line VDD, Electrode DD.

The drain electrode DD of the driving thin film transistor DTr is connected to the first electrode 111 of the light emitting diode E.

An organic light emitting layer 113 is interposed between the first electrode 111 and the second electrode 115.

3, the semiconductor layer 103 is located on the switching region TrA of each of the sub-pixels R-SP, G-SP, and B-SP on the substrate 101, The layer 103 is made of silicon and its central portion is composed of an active region 103a forming a channel and source and drain regions 103b and 103c doped with a high concentration of impurities on both sides of the active region 103a.

A gate insulating film 105 is disposed on the semiconductor layer 103.

A gate electrode DG corresponding to the active region 103a of the semiconductor layer 103 and a gate wiring GL extending in one direction although not shown in the drawing are provided on the gate insulating film 105.

The first interlayer insulating film 109a and the gate insulating film 105 under the first interlayer insulating film 109a are disposed on the upper portion including the gate electrode DG and the gate line GL, And first and second semiconductor layer contact holes 116 exposing the source and drain regions 103b and 103c located on both sides of the first semiconductor layer contact hole 103a.

Next, upper portions of the first interlayer insulating film 109a including the first and second semiconductor layer contact holes 116 are connected to the source and drain regions (the first and second semiconductor layer contact holes 116) Source and drain electrodes DS and DD, respectively, which are in contact with the source electrodes 103a and 103b and 103c, respectively.

The second interlayer insulating film 109b is located above the first interlayer insulating film 109a exposed between the source and drain electrodes DS and DD and the two electrodes DS and DD.

At this time, the semiconductor layer 103 including the source and drain electrodes DS and DD and the source and drain regions 103b and 103c in contact with the electrodes DS and DD and the gate The insulating film 105 and the gate electrode DG constitute a driving thin film transistor DTr.

Though not shown in the drawing, the switching thin film transistor STr has the same structure as the driving thin film transistor DTr and is connected to the driving thin film transistor DTr.

The switching thin film transistor STr and the driving thin film transistor DTr are exemplified by a top gate type in which the semiconductor layer 103 is formed of a polysilicon semiconductor layer or an oxide semiconductor layer, Or a bottom gate type of pure and impurity amorphous silicon.

In this case, when the semiconductor layer 103 is formed of an oxide semiconductor layer, a light shielding layer (not shown) may be further disposed under the semiconductor layer 103, and a buffer layer (not shown) may be interposed between the light shielding layer City) can be located.

The color filters 106a, 106b, and 106c are located above the second interlayer insulating film 109b corresponding to the light emitting region EA of each of the sub-pixels R-SP, G-SP, and B-SP.

The color filters 106a, 106b and 106c are for converting the color of the white light emitted from the organic light emitting layer 113 and include a red color filter 106a, a blue color filter 106b, ) Color filter 106c is positioned on the light emitting region EA of each of the sub-pixels R-SP, G-SP, and B-SP, G-SP, and B-SP) to emit R, G, and B colors, resulting in a high-brightness full-color image.

Here, the OLED 100 according to the embodiment of the present invention is characterized in that the reflective barrier 200 is further disposed on the second interlayer insulating film 109b.

The reflective barrier 200 is located along the edge of the non-emission area NEA of each of the sub-pixels R-SP, G-SP, and B- G-SP, and B-SP), and has a side surface having a reverse taper.

The OLED 100 according to the embodiment of the present invention improves the light extraction efficiency and is reflected from neighboring sub-pixels R-SP, G-SP, and B-SP, It is possible to minimize the occurrence of light leakage.

Let's take a closer look at this later.

A drain contact hole PH for exposing the drain electrode DD of the driving thin film transistor DTr together with the second interlayer insulating film 109b is formed on the reflective barrier 200 and the color filters 106a, 106b and 106c Overcoat layer 108 is located.

A first electrode (anode) of the light emitting diode E is connected to the drain electrode DD of the driving thin film transistor DTr on the overcoat layer 108, 111).

The first electrode 111 is positioned for each of the sub-pixels R-SP, G-SP, and B-SP. A bank 119 is positioned between the banks 111 and 111. That is, the first electrode 111 is divided into sub-pixels R-SP, G-SP, and B-SP by using the banks 119 as boundaries for the sub-pixels R-SP, And has a separate structure.

The organic light emitting layer 113 is disposed on the first electrode 111 and the second electrode 115 is formed on the organic light emitting layer 113. The second electrode 115 is a cathode.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to a selected signal, the OLED 100 emits light to the OLED 100 through the holes injected from the first electrode 111 and the holes supplied from the second electrode 115 Electrons are transported to the organic light emitting layer 113 to form an exciton. When the excitons transit from the excited state to the ground state, light is generated and emitted in the form of visible light.

At this time, the emitted light passes through the transparent first electrode 111 and exits to the outside, so that the OLED 100 realizes an arbitrary image.

The OLED 100 according to the embodiment of the present invention further positions the reflective barrier 200 along the edges of the sub-pixels R-SP, G-SP, and B-SP on the second interlayer insulating film 109b The light extraction efficiency of the OLED 100 can be improved and the light leakage generated from the neighboring sub-pixels R-SP, G-SP, and B-SP can be minimized.

FIG. 4 is a view schematically showing a light guide of an OLED according to an embodiment of the present invention. Referring to FIG.

As shown in the drawing, red sub-pixels R-SP and green sub-pixels G-SP are arranged adjacent to each other with a non-emission region NEA corresponding to the data line DL interposed therebetween on the substrate 101 The red color filter 106a is located above the second interlayer insulating film 109b of the light emitting area EA of the red sub pixel R-SP and the light emitting area EA of the green sub pixel G- The green color filter 106b is located above the second interlayer insulating film 109b.

An upper portion of the second interlayer insulating film 109b in the non-emitting region NEA between the light emitting region EA of the red sub-pixel R-SP and the light emitting region EA of the green sub-pixel G- The reflective barrier 200 is located.

The reflective barrier 200 is composed of opposite side surfaces 201 of reverse taper and a lower surface 203 and an upper surface 205 connecting both side surfaces 201 so that the sectional shape thereof is away from the second interlayer insulating film 109b Trapezoidal shape in which the recording width is widened.

In addition to the inverted trapezoidal shape, the reflective barrier ribs 200 may be formed in any shape in which the opposite side surfaces 201 have an inverted taper structure, for example, an inverted triangular shape.

At this time, when the reflective barrier 200 is formed in an inverted triangular shape, the lower surface 203 may be omitted.

Here, the reverse tapered structure means that both sides 201 facing each other are tilted so as to have a narrow width toward the direction of light emitted from the organic light emitting layer 113.

The reflective barrier 200 may be made of a variety of materials, for example, photodefinable acryl, photoresist, silicon oxide (SiO2), silicon nitride (SiNx) , Poly (methyl methacrylate) (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy, and polyester.

The bank material may be a resin or paste containing an organic resin, a glass paste and a black pigment, a metal particle such as nickel, aluminum, molybdenum and an alloy thereof, Metal oxide particles (e.g., chromium oxide), or metal nitride particles (e.g., chromium nitride).

A reflective layer 210 is provided on both the side surfaces 201 and the upper surface 205 of the reflective barrier 200.

The reflective layer 210 may be formed of any material capable of reflecting light such as titanium dioxide, aluminum, aluminum oxide, barium sulfate, calcium carbonate, calcium sulfate, magnesium sulfate, barium carbonate, zinc oxide, magnesium hydroxide Calcium hydroxide or talc is deposited on both side surfaces 201 and the upper surface 205 of the reflective barrier 200.

Thus, the reflective barrier 200 has a reflective side 201 of reverse taper.

The red color filter 106a and the green color filter pattern 106b and the overcoat layer 108 are located on the upper part of the reflective barrier 200. The red sub-pixel R-SP and the green sub-pixel G- The first electrode 111 is provided for each of the sub-pixels R-SP and G-SP on the overcoat layer 108 corresponding to the light emitting region EA of the first electrode 111, The organic light emitting layer 113 and the second electrode 115 are sequentially stacked to form a light emitting diode E.

The substrate 101 on which the light emitting diodes E are formed is encapsulated by the protective film 102.

At this time, in correspondence to the non-emission region NEA between the first electrode 111 located on the red sub-pixel R-SP and the first electrode 111 located on the green sub-pixel G-SP, The bank 119 has a width D2 that is wider than the width D1 of the reflective barrier 200 on the non-emission area NEA and the reflective barrier 200 Is prevented from being viewed.

The OLED 100 according to the embodiment of the present invention includes a reflective barrier 200 having a reflective side 201 of a reverse taper along the edge of each of the sub-pixels R-SP and G-SP. Emitting region NEA can be extracted to the outside. Thus, the light extraction efficiency is improved.

Light emitted from the organic light emitting layer 113 is transmitted through the organic light emitting layer 113 and the first electrode 111 to the organic light emitting layer 113 and the first electrode 111, The optical path is not changed at the interface of the optical waveguide.

The refractive index of the organic light emitting layer 113 and the first electrode 111 may be 1.7 to 2.0.

At this time, since the refractive index of the overcoat layer 108 is about 1.5, the light emitted from the organic light emitting layer 113 is totally reflected at the interface between the first electrode 111 and the overcoat layer 108. At this time, Some of the light totally reflected on the interface between the overcoat layer 108 and the overcoat layer 108 travels to the light emitting area EA of each of the sub-pixels R-SP and G-SP, Emitting region EA located between the emission regions EA of the respective sub-pixels R-SP and G-SP without going to the emission region EA of each of the sub-pixels R-SP and G-SP. ).

The light L2 traveling to the non-light emitting region NEA has an angle larger than the total reflection critical angle and can not transmit through the substrate 101 and is totally reflected at the boundary of the substrate 101 and is not emitted to the outside of the substrate 101, do.

The OLED 100 according to the embodiment of the present invention allows the light L2 traveling to the non-emission area NEA to be reflected by the reflective barrier 200 and extracted to the outside of the substrate 101 .

That is, the reflective barrier 200 provided with the reflective layer 210 controls the reflection angle of the light incident through the reflective side 201 on which the light L2 traveling to the non-emission area NEA is reflected. In this case, The light L2 traveling to the non-emission area NEA is reflected by the reflective side 201 of the reverse taper so that light at a specific angle Thereby preventing total internal reflection.

The light L2 traveling to the non-light emitting region NEA is reflected toward the light emitting region EA by the reflective side 201 of the reverse taper, (100 in FIG. 3) according to the embodiment of the present invention is improved in light extraction efficiency.

That is, a part of the light L1 of light L1, L2 emitted from the organic light emitting layer 113 of the green sub-pixel G-SP proceeds to the light emitting area EA and is transmitted through the green color filter 106b, Emitting region EA of the green sub-pixel G-SP and the light-emitting region EA of the red sub-pixel R-SP, Emitting region NEA.

At this time, the light L2 traveling to the non-emission area NEA is reflected by the reflective side 201 of the reflective barrier 200 to travel toward the emission area EA of the green sub-pixel G-SP, And is emitted to the outside of the substrate 101.

Accordingly, the light extraction efficiency is improved, thereby improving the luminance of the OLED (100 in FIG. 3) and also preventing the power consumption of the OLED (100 in FIG. 3) from rising.

Also, as the light extraction efficiency is improved as described above, the lifetime of the light emitting diode E is also increased.

In addition, the OLED according to the embodiment of the present invention (100 in FIG. 3) can also minimize the light leakage generated from the neighboring sub-pixels R-SP and G-SP.

A part of light emitted from the organic light emitting layer 113 toward the substrate 101 may be partially transmitted through a metal wiring such as a data line DL provided on the substrate 101, And reaches the adjacent sub-pixels R-SP and G-SP, thereby generating light leakage.

That is, in the process in which the lights L1, L3, and L4 emitted from the organic light emitting layer 113 of the green sub-pixel G-SP pass through the green color filter 106b and the substrate 101 and are emitted to the outside, The light L3 and L4 are reflected by the metal wiring such as the data line DL and travel toward the red sub-pixel R-SP so that light leakage due to the green light is generated in the red sub-pixel R-SP .

3, the OLED 100 according to the embodiment of the present invention includes the reflective barrier 200 in the non-emission region NEA along the edge of each of the sub-pixels R-SP and G-SP, And blocks the light L3 from reaching the sub-pixels R-SP and G-SP.

Therefore, the light leakage generated by reflection from the adjacent sub-pixels (R-SP, G-SP) can be minimized.

Further, the light L4 reflected and generated from the adjacent sub-pixels R-SP and G-SP is reflected again to be extracted to the outside, whereby the light extraction efficiency of the OLED (100 in FIG. 3) .

FIG. 5A is a simulation result of measuring the light guided state of the OLED not including the reflective barrier, FIG. 5B is a simulation result of measuring the light guided state of the OLED in which the reflective barrier is located according to the embodiment of the present invention to be.

FIGS. 5C to 5E are simulation results of a light guiding manner according to an inverse taper angle formed by the reflective side of the reflective barrier, and FIG. 6 is a cross-sectional view schematically illustrating the reflective barrier according to an embodiment of the present invention .

The inverse taper angle? Formed by the reflective lateral face 201 of the reflective barrier 200 is 56.3 degrees and the refractive index of the organic light emitting layer 113 and the first electrode 111 is 1.7 to 1.8, The refractive index of the substrate 108 and the substrate 101 is 1.5.

Referring to FIGS. 5A and 5B, total reflection occurs at the interface between the first electrode 111 and the overcoat layer 108, and it is confirmed that light travels to the non-emission region NEA.

In this case, as shown in FIG. 5A, the OLED not including the reflective barrier can be confirmed that the light traveling to the non-emission region NEA is totally reflected at the boundary of the substrate 101.

As a result, the light can not be emitted to the outside of the substrate 101 and is trapped.

5B, an OLED (100 in FIG. 3) including a reflective barrier 200 is totally reflected at an interface between the overcoat layer 108 and the first electrode 111 to form a non-emission region NEA, Is reflected by the reflective side surface 201 of the reflective barrier 200 and is extracted to the outside of the substrate 101.

Accordingly, the OLED (100 in FIG. 3) according to the embodiment of the present invention is arranged above the second interlayer insulating film (109b in FIG. 4) It can be seen that the light extraction efficiency of the OLED (100 in FIG. 3) can be improved by further positioning the partition 200.

Referring to FIGS. 5C to 5E and FIG. 6, light guided according to the inverse taper angle? Formed by the reflective side surface 201 of the reflective barrier 200 according to the embodiment of the present invention I'll see.

The reverse taper angle? Formed by the reflective side 201 of the reflective barrier 200 in FIG. 5C is 45 degrees and the reverse taper angle? Formed by the reflective side 201 of the reflective barrier 200 in FIG. (?) Is 72 degrees, and the reverse taper angle? Made by the reflective side surface 201 of the reflective partition 200 in FIG. 5E is 90 degrees.

5C to 5E and 5B together, when the inverse taper angle? Formed by the reflective lateral face 201 of the reflective barrier 200 is 45 degrees and 72 degrees, When the reverse taper angle? Formed by the reflective side surface 201 of the reflective barrier 200 is 56.3 degrees, the light reflected by the reflective barrier 200 emerges toward the front side .

Accordingly, the inverse taper angle? Formed by the reflective lateral face 201 of the reflective barrier 200 can be adjusted to improve the frontal brightness or the lateral brightness.

5E, when the inverse taper angle? Formed by the reflective side surface 201 of the reflective barrier 200 is 90 degrees, the light reflected by the reflective side surface 201 of the reflective barrier 200 Is again totally reflected at the boundary of the substrate 101. [ Accordingly, when the inverse taper angle? Formed by the reflective lateral face 201 of the reflective barrier 200 is 90 degrees, the light can not be emitted to the outside of the substrate 101 and is trapped.

Therefore, it is desirable that the inverse taper angle? Formed by the reflective side surface 201 of the reflective barrier 200 is designed to be 90 degrees or less.

The width D1 of the upper surface 205 of the reflective barrier 200 is widened when the reverse taper angle formed by the reflective side 201 of the reflective barrier 200 is 45 degrees or less. Since the width of the non-emission area NEA in which the reflective side surface 201 is located should be increased, the reverse taper angle? Formed by the reflective side surface 201 should preferably be 45 degrees or more.

As the reverse taper angle? Formed by the reflective side surface 201 of the reflective barrier 200 is lower, the reflective surface is reflected at a position near the lower surface 203 of the reflective barrier 200, The thickness h of the reflective barrier 200 must be increased in order to reduce the reverse taper angle?

Increasing the thickness h of the reflective barrier 200 also increases the overall thickness of the OLED 100 as shown in Figure 3 so that the inverse taper angle? .

The reflective layer 210 provided on both the side surfaces 201 and the upper surface 205 of the reflective barrier 200 may be formed on the tail surface of the reflective layer 210 near the lower surface 203 during the deposition of the reflective layer 210 the tail 220 may not be exposed to the outside of the upper surface 205 of the reflective barrier 200 so that the tail 220 may not be visible to the outside.

The tail 220 can be exposed to the outside of the upper surface 205 of the reflective barrier 200 as the inverse taper angle? Formed by the reflective side 201 of the reflective barrier 200 is greater, The inverse taper angle? Formed by the reflective side surface 201 of the reflective layer 210 is within 90 degrees or below which the light can be extracted to the outside of the substrate 101, 200 so as not to be exposed to the outside of the upper surface 205 thereof.

As described above, the OLED (100 in Fig. 3) according to the embodiment of the present invention is defined along the edge of the light emitting region (EA in Fig. 4) of each sub pixel (R-SP, G-SP in Fig. 4) (R-SP, G-SP in FIG. 4) by positioning the reflective barrier 200 having the reflective side 201 of the reverse taper in correspondence with the non-emission area (NEA in FIG. 4) It is possible to reflect light (L2 in FIG. 4) traveling to the non-light emitting region (NEA in FIG. 4) of light and extract the light outside the substrate 101.

This improves the light extraction efficiency of the OLED (100 in FIG. 3).

Further, it is possible to minimize the light leakage generated by reflection from the adjacent sub-pixels (R-SP, G-SP in FIG. 4) (L4 in FIG. 4) is reflected again and extracted to the outside, thereby further improving the light extraction efficiency of the OLED (100 in FIG. 3).

In the above description, one unit pixel (P in FIG. 3) is made up only of red, green and blue sub-pixels (R-SP, G-SP and B-SP in FIG. 3) The white pixel may be further included in the unit pixel (P in FIG. 3), and a white color filter may be separately disposed in the white sub-pixel, or the white light realized from the organic light emitting layer It can also be implemented.

The red, green, and blue color filters (106a, 106b, and 106c in FIG. 3) are omitted in each of the sub-pixels (R-SP, G-SP, and B- Red, green, and blue from the organic light emitting layer (113 in FIG. 3) located in the R-SP, G-SP,

At this time, the organic light emitting layer (113 in FIG. 3) located in each sub-pixel (R-SP, G-SP, B-SP in FIG. 3) may have various thicknesses depending on the color to be implemented.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

101, 102: substrate, protective film
105: gate insulating layer
106a, 106b, and 106c: red, green, and blue color filters
108: overcoat layer
109a and 109b: first and second interlayer insulating films
111: first electrode, 113: organic light emitting layer, 115: second electrode
119: Bank
200: reflective barrier 201 (reflective side, 203: lower surface, 205: upper surface, 210: reflective layer)
DL: Data wiring
EA: emission region, NEA: non-emission region
R-SP, G-SP: red and green sub-pixels

Claims (7)

A substrate including a plurality of sub-pixels each defining a light emitting region and a non-emitting region along an edge of the light emitting region;
A reflective barrier located corresponding to the non-emission area and including a reflective side;
An overcoat layer positioned above the reflective barrier;
A light emitting diode including a first electrode sequentially disposed on the overcoat layer, an organic light emitting layer, and a second electrode,
Wherein the reflective barrier has an inverted taper so that a width of the reflective barrier increases toward a direction of light emitted from the organic light emitting layer.
The method according to claim 1,
The reflective barrier may have a rectangular shape formed along an edge of each of the light emitting regions and may include both reflective surfaces and upper surfaces connecting the both surfaces. Display device.
3. The method of claim 2,
Wherein the reflective barrier is at least one of an inverse trapezoidal shape or an inverted triangular shape in which a width of the reflective barrier is wider from the substrate.
The method according to claim 1,
Wherein an inverse taper angle between the substrate and the reflective side is between 45 degrees and 90 degrees.
The method according to claim 1,
The first electrode is positioned for each sub-pixel, the bank is located in the non-emission region along the edge of the first electrode,
Wherein the width of the reflective barrier is narrower than the width of the bank.
The method according to claim 1,
Wherein the plurality of sub-pixels include a red sub-pixel having a red color filter on the light emitting region, a green sub-pixel having a green color filter, and a blue sub-pixel having a blue color filter.
The method according to claim 6,
Each of the sub-pixels includes a driving thin film transistor,
The driving thin film transistor includes a semiconductor layer, a gate insulating film located above the semiconductor layer, a gate electrode positioned above the gate insulating film, a first interlayer insulating film located above the gate electrode, a source located above the first interlayer insulating film, And a drain electrode,
Wherein the reflective barrier and the red, green, and blue color filters are positioned above the second interlayer insulating film located above the source and drain electrodes.

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